u/No-Temporary4325

I've spent the last few weeks going deep on the AI observability space LangSmith, Braintrust, AgentOps, Langfuse, all of it. They're all great at one thing: telling you what happened. Traces, spans, evals, metrics.

That's not really my problem when I'm vibe coding though. My problem is dumber than that.

An agent makes 30 changes in a row. Everything looks fine at the time. Some time later I notice something's not working right. Now I have no real way to know which of those 30 changes was the actual cause.

So I end up either re-prompting and hoping, manually bisecting through the session myself, or just reverting a big chunk of work and starting over.

What I keep wishing existed is something that sits there while I'm coding, checkpointing as it goes, and the moment something stops working, it actually runs the tests/compile checks right then and tells me exactly which step caused it with proof, not a guess and lets me jump back to right before that step. Bonus if it remembers the failure so it doesn't happen again, and if it can eventually trace a live production issue back to the session that introduced it.

Does something like this already exist and I've just missed it? Or is this a problem I've mostly invented from watching one too many long sessions go sideways?

So I've spent the last few weeks going deep on the AI observability space LangSmith, Braintrust, AgentOps, Langfuse, all of it. And they're all really good at one thing: telling you what happened. Traces, spans, evals, metrics, the whole deal.

But that's not actually my problem when I'm vibe coding with Claude Code (or Cursor, or whatever). My problem is way dumber than "observability."

It's this: Claude makes like 30 changes in a row. Everything looks fine while it's happening. Then twenty minutes later I notice something's broken. And now I genuinely have no idea which of those 30 changes did it.

So I end up doing one of three things, none of which I'm proud of:

• keep re-prompting and just... hope, burning tokens the whole time
• manually git bisect through my own session like some kind of detective
• or just rage-revert half the project and pretend that was the plan all along

What I keep wishing existed is something that sits there while I'm coding, not something I check after I've already deployed. Not "here's what happened" more like it's watching in real time, checkpointing as it goes, and when something breaks it actually runs the tests/compile checks/whatever right then and there and tells me "yeah step 17 broke your auth, here's the proof, click here to go back to step 16" instead of me guessing or it guessing.

And then ideally it remembers that failure so the same mistake doesn't happen again next week. And down the line, if that same code breaks in production, it can trace it back to the exact session that wrote it.

So is there already something like this and I've just missed it? Or is this a "problem I invented because I've watched Claude confidently destroy my codebase one too many times" situation? Genuinely can't tell anymore lol.